[Lf] [Fwd: LF: RE: G0MRF/SM6LKM DDS VFO and Jason]

[Andre Kesteloot]

Talbot Andrew wrote:

> >From John Bodin
> >It would be very nice if we could agree on a simple serial protocol
> >that would allow any PC program, be it DOS or Windoze, to take total
> >control over the DDS (I know that Andy G4JNT has done something
> >in this direction).
>
> My DDS control protocol allows the 32 bit frequency word or 5 bit phase to
> be sent as printable Ascii hex characters using a simple serial protocol
> with simple handshaking, useable from any terminal or driver software, at
> 19200 baud.  Driver software reads back user data from the DDS controller to
> let this know the clock frequency.  That way, the software can be
> independant of any particular DDS unit it has to control. (Very useful when
> you have five DDS modules in the shack operating from clocks ranging from 5
> MHz up to 94.45 MHz and soon 4.194304MHz as well)  There is also a module
> address facility built in (thanks to Larry for that idea) to allow multidrop
> use where one serial line can control several DDS units, a-la Icom C-IV
> interface.  Last option is a command that updates the frequency or phase in
> the DDS only after an external trigger pulse.  This makes GPS timed PSK or
> FSK straightforwrd, after the new value is sent to the DDS controller, the
> new value will appear exactly 3.2us after the UTC timing pulse.
>
> Summary of the DDS module commands :
>
> ------------------------------------
> The first character sent is a Board Address which precedes all commands.
> This is a single Hex character sent as ASCII  0 - F and potentially allows
> up to 16 modules to be driven from the same COM port.  If correctly
> addressed, the module responds with a Z [cr][lf] and this response sould be
> waited for
>
> The next character is a command which may have hex data following it.
>
> Q       Followed by eight hex digits for the frequency command word
> terminated by a  carriage return
> P       Followed by two hex digits for phase word and [cr]
> U       Writes the data sent above to the AD9850 DDS chip
> T       Writes the data  to the AD9850 after the next 0/1 transition on the
> external trigger input
> W       As for U, but also stores the data in the PIC's non-volatile EEPROM
> memory for switch on next time.
> Y       Followed by one Hex digit, changes the board address and stores in
> EEPROM.  No [cr] needed
> K       Followed by 10 hex digits & [cr]. Read back user data, usually clock
> frequency
> R       Readback current data values in operation - not necessarily those in
> EEPROM
>
> So, to update the frequency (to one mentioned a lot on this reflector :-|
> the following characters are sent assuming the board address is 7  The dot
> .  means wait for a response :
>
> 7.Q06F58E8C[cr]
> 7.U
>
> Andy  G4JNT
>
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